Hi LamboWalker,
Many GMATers spend 3 months (or more) of consistent study time before they hit their 'peak' scores, so the type of pre-study that you're thinking about is probably not necessary. If you're interested in focusing on the GMAT now, then that would be a smart choice (since working to lock-in that type of high Score years in advance of when you will actually "need" it would give you the advantage of not having to focus on any of the other aspects of your applications).
If you do decide that want to formally start your studies now (and commit to that timeframe and routine), then it would be a good idea to take a FULL-LENGTH practice CAT Test; you can access 2 for free at
www.mba.com (and they come with some additional practice materials). If you want to do a little studying first, so that you can familiarize yourself with the basic content and question types, then that's okay - but you shouldn't wait too long to take that initial CAT. That score will give us a good sense of your natural strengths and weaknesses and will help provide a basis for comparison as you continue to study. A FULL CAT takes about 3.5 hours to complete, so make sure that you've set aside enough time to take it in one sitting. Once you have that Score, you should report back here and we can come up with a study plan.
I'd like to know a bit more about your timeline and goals:
1) What is your goal score?
2) What Schools/Programs are you planning to apply to?
3) If you were to start your studies now, then how many hours do you think you can consistently study each week?
GMAT assassins aren't born, they're made,
Rich